Important Watches, Pocket Watches and...

Noga Hilton Hotel, Nov 13, 2005

LOT 38

?Pocket Chronometer with ?Z? balance? Thomas Earnshaw, Invenit et Fecit, No. 429 of the sort/2660. Case by Thomas Carpenter with London hallmarks for 1800. Very fine and rare, gold pair-cased pocket chronometer with Earnshaw?s spring detent escapement and Earnshaw?s ?Z? compensation balance.

CHF 20,000 - 30,000

EUR 13,000 - 20,000 / USD 16,000 - 23,000

Sold: CHF 12,650

C. Outer: two-body, polished. Inner: two-body, ?bassine?, polished. D. White enamel, radial Roman numerals, outer minute track, subsidiary seconds. Gold ?heart and poker? hands. M. 40 mm. secured by screws, gilt full-plate with cylindrical pillars, fusee and chain with Harrison?s maintaining power, Earnshaw spring detent escapement, escape wheel jeweled with endstones in screwed chatons, Earnshaw?s ?Z? bimetallic compensation balance with sliding timing weights and two steel mean time screws, single-footed cock with endstone in screwed chaton, free-sprung blued steel helical balance-spring. Dial and movement signed and numbered. Diam. 65 mm.


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Grading System
Grade: AAA

Excellent
Case: 3

Good
Movement: 3*

Good

Overhaul recommended, at buyer's expense
Dial: 3-01

Good

HANDS Original

Notes

Using Earnshaw?s numbering system, the first number is the number of watches made at that point using Earnshaw?s spring detent escapement. The second number, in this case 2660, is the total number of watches produced at that point. Thomas Earnshaw (1749 ? 1829) Born in Ashton-Under-Lyne in Lancashire, by 1780 he had the reputation of being a very fine watch finisher. He invented the modern chronometer spring detent escapement towards the end of 1780, a design that he insisted was stolen by Arnold. However, it is likely that Earnshaw and Arnold arrived at their conclusions separately. Earnshaw perfected the fusing together of brass and steel to make laminae for compensation balances which previously had had to be riveted.